Federal Trade Commission v. Morton Salt Company

Morton Salt Company (defendant) priced table salt on a quantity-discount scale, but only five companies were large enough to actually purchase the volumes needed to reach the lowest price tier, letting those five sell salt at retail prices lower than the wholesale prices available to their smaller competitors. The FTC (plaintiff) challenged the scheme as illegal price discrimination under the Robinson-Patman Act; Morton argued the discount wasn't discriminatory because it was open to any buyer who purchased the qualifying quantity, and partly justified it by claiming large quantities were cheaper to ship, and the court of appeals agreed with Morton.